JP6225398B2 - Wireless communication apparatus, accommodation prediction apparatus, accommodation prediction method, and program - Google Patents

Description

  The present invention relates to a wireless communication apparatus and the like that perform prediction related to availability of wireless communication.

  In recent years, with the spread of wireless communication systems using an ISM band such as a wireless LAN and Bluetooth (registered trademark), applications using the wireless communication system have been rapidly developed in various fields. In a wireless system that accommodates such applications, satisfactory operational quality required by each application, scalability of the number of wireless nodes, and the like are required.

  In an environment where there are multiple autonomous distributed wireless communication systems in which the number of wireless nodes, distance between nodes, etc. change from moment to moment, dynamic wireless communication systems are being studied to fulfill more application requirements. . As such a channel access system, a CSMA / CA system based on IEEE 802.11 is assumed from the viewpoint of coexistence with other radio systems and ensuring scalability of the number of accommodated nodes. .

  In the conventional 802.11 system, each wireless base station (AP: access point) and wireless terminal device (STA: station) try to secure resources. For this reason, even when the available radio resources of the system itself cannot be obtained sufficiently, there may occur a situation where application traffic exceeding the limit of the radio resources is allowed to flow. The overall quality deteriorates in a chained manner. In order to solve such a problem, it has been proposed to perform prediction regarding the possibility of accommodating wireless communication to be started (see, for example, Non-Patent Document 1).

Mariko Sekiguchi, Hitoshi Yano, Masayuki Ariyoshi, Kiyoshi Kobayashi, “Achieving QoS Prediction Method for Wireless LAN for Improving Application Operation Quality in Frequency Sharing Environment”, IEICE Technical Report, SR2013-36, p. 91-98, July 2013

  In the conventional example described in Non-Patent Document 1, using boundary information indicating the relationship between the usage status of the own cell and the usage status of other cells according to the boundary of the radio communication accommodation limit in the own cell, A prediction is made regarding whether or not wireless communication can be accommodated. However, as described in Non-Patent Document 1, it has been confirmed that the boundary depends on various parameters such as the number of wireless terminal devices of the own cell and other cells, and the packet size of the IP layer. . On the other hand, there are an infinite number of such parameters and combinations of the parameters, and it is practically difficult to set boundaries by grasping information on all parameters. Therefore, it is difficult to appropriately set the boundary according to the state of wireless communication, and as a result, there is a problem that the accuracy of prediction regarding the availability of wireless communication is lowered. In addition, the accuracy of the prediction is reduced. For example, when it is predicted that the wireless communication can not be accommodated, the wireless communication that cannot be accommodated is performed, and the quality of the wireless communication cannot be ensured. . For example, when it is predicted that the wireless communication can be accommodated but cannot be accommodated, the wireless resource cannot be effectively used.

  The present invention has been made to solve the above-described problems, and provides a wireless communication device and the like that can improve the accuracy of prediction regarding whether or not wireless communication can be accommodated by appropriately adjusting the boundary. With the goal.

In order to achieve the above object, an accommodation prediction device according to the present invention includes an own cell utilization status acquisition unit that acquires an own cell current usage status that is a current radio resource usage status of an own cell in which the radio communication device performs radio communication, The other cell usage status acquisition unit for acquiring the current usage status of the other cell that is the current radio resource usage status of the other cell that may interfere with the own cell, and the current cell current usage status and the current usage status of the other cell. The own cell's own cell usage status and the other cell's radio resource usage status of other cell usage status can be stored in the own cell. The own cell usage status and other cell usage status according to the boundary between the own cell usage status and other cell usage status when the host cell is not able to accommodate wireless communication in the own cell and the other cell usage status Use Can be accommodated by the prediction unit, which predicts whether or not the wireless communication can be accommodated, using the boundary information indicating the relationship with the situation, the relational expression identified by the relational expression identifying unit, and the current use status of the own cell. When the radio resource allocation of the own cell is changed so that the range is predicted to exist, a determination unit that determines whether or not the wireless communication can be accommodated in the own cell after the change, and according to a determination result by the determination unit An adjustment unit that adjusts the boundary information, and the prediction unit performs prediction using the boundary information adjusted by the adjustment unit.
With such a configuration, the boundary information can be adjusted depending on whether or not the radio communication is accommodated after changing the radio resource allocation according to the prediction, and the prediction accuracy regarding the availability of the radio communication can be improved. Accordingly, the prediction accuracy can be improved without setting the boundary information using various parameters. Further, by repeating the adjustment of the boundary information, it is possible to realize appropriate radio resource allocation according to the temporal change of the radio resource usage status.

In the accommodation prediction device according to the present invention, the adjustment unit may adjust the boundary information so that the area that cannot be accommodated increases when the determination unit determines that the wireless communication cannot be accommodated in the own cell. Good.
If it is predicted that radio communication can be accommodated but the radio communication cannot be accommodated, the area that cannot be accommodated may be larger. Therefore, in such a case, with such a configuration, the boundary information is adjusted, and the area that is determined to be accommodable is reduced, so that in the subsequent prediction, the accomodation is predicted. Nevertheless, it is possible to reduce the situation of failure to accommodate wireless communication, and to improve the accuracy of prediction.

Further, in the accommodation prediction device according to the present invention, wireless communication is performed by a plurality of applications, the determination unit determines whether the wireless communication can be accommodated in its own cell for each application, and the adjustment unit If the determination unit determines that the wireless communication could not be accommodated in the cell, the boundary information is adjusted so that the greater the number of applications that are determined to be unacceptable, the more areas that cannot be accommodated. Also good.
With such a configuration, it is possible to shorten the period until convergence to appropriate boundary information.

In the accommodation prediction device according to the present invention, the adjustment unit may adjust the boundary information so that the area that can be accommodated increases when the determination unit determines that the wireless communication can be accommodated in the own cell.
As expected that radio communication can be accommodated, if the radio communication is successfully accommodated, there is a possibility that the area that can be accommodated is wider. Therefore, in such a case, with such a configuration, by increasing the area that is determined to be accommodable, in the subsequent prediction, the range that is predicted to be accommodable is expanded, and the prediction The accuracy can be improved.

Further, in the accommodation prediction device according to the present invention, the prediction unit predicts the own cell usage status and the other cell usage status according to the change of the radio resource allocation of the own cell in the accommodable range using the relational expression, When the radio resource allocation of the own cell is changed so that the own cell usage situation predicted by the prediction unit is changed, the determination unit determines whether the radio communication can be accommodated in the own cell after the change. The current use of the own cell after the assignment of the radio resource in the own cell is changed so that the own cell usage state predicted by the judgment unit and predicted by the prediction unit is determined to be able to accommodate the radio communication in the own cell. Boundary so that the area that can be accommodated increases when the status and current usage status of other cells are within a predetermined range from the usage status of the own cell and other cell usage status predicted by the prediction unit It may adjust the broadcast.
When the prediction error is smaller than a predetermined threshold, the occurrence of radio signal collision is small, and it is considered that there is room in the radio communication accommodation status. Therefore, in such a case, it is considered that the accuracy of prediction can be improved by adjusting the boundary information with such a configuration.

The accommodation prediction device according to the present invention further includes a history information accumulation unit that accumulates history information including at least a past determination result by the determination unit, and the adjustment unit automatically determines the determination result according to the adjusted boundary information. When it is predicted that the wireless communication cannot be accommodated in the cell using the history information accumulated by the history information accumulation unit, the adjustment may not be performed.
With such a configuration, when it is predicted that radio communication accommodation failure will occur due to prediction using the boundary information after adjustment, by making such unnecessary adjustments, Accuracy can be improved. For example, when both the adjustment for increasing the accommodable range and the adjustment for decreasing are performed, the adjustment for increasing the accommodable range and the adjustment for decreasing are repeated after the boundary information has properly converged. As a result, the prediction accuracy may be reduced. Therefore, when it is found from the history information that such a situation has occurred, the accuracy of prediction can be improved by not performing adjustment.

In addition, in the wireless communication device according to the present invention, the accommodation prediction device, the communication unit that performs wireless communication, the control unit that controls the allocation of the wireless resources related to the wireless communication performed by the communication unit according to the prediction result by the prediction unit, May be provided.
With such a configuration, it is possible to perform radio resource allocation control according to the prediction result, and to avoid allocating radio resources beyond the radio resource accommodation limit.

  According to the wireless communication apparatus and the like according to the present invention, it is possible to improve the accuracy of prediction regarding the possibility of accommodating wireless communication.

1 is a block diagram showing a configuration of a wireless communication apparatus according to Embodiment 1 of the present invention. The flowchart which shows operation | movement of the accommodation prediction apparatus by the same embodiment The figure which shows an example of the relationship between the radio | wireless resource utilization rate of the own cell in the same embodiment, and the radio | wireless resource utilization rate of another cell. The figure which shows an example of the relationship between the radio | wireless resource utilization rate of the own cell in the same embodiment, and the radio | wireless resource utilization rate of another cell. The figure for demonstrating adjustment of the boundary information in the embodiment The figure for demonstrating adjustment of the boundary information in the embodiment The figure for demonstrating adjustment of the boundary information in the embodiment The figure for demonstrating adjustment of the boundary information in the embodiment The figure which shows the simulation result of case 1 in the embodiment The figure which shows the simulation result of case 1 in the embodiment The figure which shows the simulation result of case 2 in the embodiment The figure which shows the simulation result of case 2 in the embodiment Schematic diagram showing an example of the appearance of the computer system in the embodiment The figure which shows an example of a structure of the computer system in the embodiment

  Hereinafter, a wireless communication apparatus according to the present invention will be described using embodiments. In the following embodiments, components and steps denoted by the same reference numerals are the same or equivalent, and repetitive description may be omitted.

(Embodiment 1)
A wireless communication apparatus according to Embodiment 1 of the present invention will be described with reference to the drawings. The radio communication apparatus according to the present embodiment adjusts boundary information indicating the radio communication accommodation limit in accordance with the success or failure of prediction regarding the availability of radio communication.

  FIG. 1 is a block diagram showing a configuration of radio communication apparatus 1 according to the present embodiment. The wireless communication device 1 according to the present embodiment includes an accommodation prediction device 2, a communication unit 11, a control unit 12, and a processing unit 13. The accommodation prediction device 2 includes the own cell usage status acquisition unit 21, the other cell usage status acquisition unit 22, the relational expression specifying unit 23, the prediction unit 24, the determination unit 25, the history information storage unit 26, And an adjustment unit 27. The wireless communication device 1 may be, for example, a wireless base station such as an access point (AP) or a wireless terminal device such as a station (STA). The wireless communication device 1 that is a wireless terminal device may be, for example, a personal computer, a tablet terminal, a smartphone, or the like. In the present embodiment, the case where the wireless communication apparatus 1 performs wireless communication in an autonomous distributed wireless communication system will be mainly described. In this embodiment, the case where the wireless communication is wireless LAN communication will be mainly described, but the present invention is not limited to this.

  The own cell usage status acquisition unit 21 acquires the current usage status of the own cell which is the current radio resource usage status of the own cell in which the radio communication device 1 performs radio communication. This own cell current use situation may be the latest own cell use situation in the own cell, or may be a new own cell use situation that can be identified with the latest own cell use situation. Note that the own cell usage status is the radio resource usage status of the own cell. The own cell is a cell to which the wireless communication device 1 belongs. When the wireless communication device 1 is a wireless base station, the range of the wireless terminal device that performs wireless communication with the wireless communication device 1 that is the wireless base station is the own cell. When the wireless communication device 1 is a wireless terminal device, the range of the wireless terminal device that performs wireless communication with the wireless base station with which the wireless communication device 1 performs wireless communication is the own cell. Of course, the wireless communication device 1 is also included in the range. The radio resource usage status refers to the usage status of radio resources in the time direction, may be the usage rate of radio resources in the time direction, may be the usage time of radio resources per unit time, Other information indicating the usage status of the resource in the time direction may be used. This usage status may be a representative value of the usage status, for example. The representative value may be, for example, an average value or an intermediate value. The utilization rate of the radio resource of the own cell is a value obtained by dividing the time when a device belonging to the own cell performs radio communication by the observation time of the radio communication. The use time of the radio resource of the own cell is the time when a device belonging to the own cell performs radio communication during an observation period which is a unit time. Note that the scheduled use period (NAV period: Network Allocation Vector period) of the radio signal included in the radio signal may or may not be included in the time during which radio communication is performed. Also, the radio resource utilization status is usually information for each frequency band, and specifically, information for each channel. Hereinafter, in this embodiment, the radio resource utilization status of one channel is mainly described. The same applies to the radio resource utilization status of other cells described later. Further, in this embodiment, processing such as acquisition of radio resource usage status and prediction of availability of radio communication is performed for each predetermined time length (hereinafter referred to as “control slot”). . Therefore, the own cell usage status acquisition unit 21 acquires the current usage status of the own cell for each control slot. This is the same when acquiring the current use status of other cells, which will be described later.

  The own cell usage status acquisition unit 21 may acquire the current usage status of the own cell according to the carrier sense, and calculates the current usage status of the own cell according to the offered load of wireless communication in the own cell. Alternatively, the current use status of the own cell may be received from another device. When acquiring the current use status of the own cell according to the carrier sense, it is necessary to distinguish between the radio signal of the own cell and the radio signal of another cell in the sensing result. Usually, since the radio signal of the own cell can be demodulated by the radio communication device 1, the radio signal of the own cell may be distinguished from the radio signal of another cell by performing demodulation. Note that if the wireless communication apparatus 1 can only demodulate a radio signal having a transmission rate that is an essential rate, it cannot demodulate a radio signal having a transmission rate that is an optional rate. You may make it judge whether it is a radio signal of a self-cell using the control signal (for example, RTS, CTS, ACK, etc.) transmitted. In addition, when the wireless communication device 1 is a wireless base station, normally, all wireless signals of the own cell are transmitted or received, so that the wireless signal of the own cell and the wireless signal of another cell can be distinguished. . The offered load is the amount of traffic that a device that performs wireless communication intends to transmit. The device may be the wireless communication device 1 or another device belonging to the own cell. The offered load may be thought of as the requested data rate of the application layer. For example, when an application requests 10 Mb / s wireless communication, the offered load is “10 Mb / s”. For example, the own cell usage status acquisition unit 21 may receive the offered load of the own cell from the application layer of the own device, may receive it from another device, or may predict it. As a case of receiving from another device, for example, when the wireless communication device 1 that is a wireless base station receives an offered load from each wireless terminal device in its own cell, or when the wireless communication device 1 that is a wireless terminal device is In some cases, the offer load of the own cell is received from the radio base station of the own cell. Moreover, as a case where it estimates, for example, when estimating application traffic based on the traffic pattern of the own cell (for example, when estimating that it is VoIP of U (Kb / s) about a certain wireless communication), In some cases, the throughput of each traffic in the own cell is estimated and the throughput is set as the offered load of the own cell. In addition, when calculating the own cell current use situation using the offered load, information such as the transmission rate of traffic and the packet size according to the offered load is also required. For example, the wireless communication device 1 that is a wireless terminal device may receive the transmission rate from the wireless base station of its own cell. In addition, the wireless communication device 1 as a wireless base station naturally knows the transmission rate of wireless communication with each wireless terminal device. Further, the wireless communication device 1 can also acquire the transmission rate and the packet size by observing the wireless communication of the own cell. When receiving the current cell current usage status from another device, for example, the radio communication device 1 that is a radio terminal device may receive the current cell current usage status from the radio base station. The acquired current use status of the own cell may be temporarily stored in a recording medium (not shown).

  Here, a method for calculating the current use state of the own cell using the offered load, the transmission rate, and the like will be described. The approximate value of the radio resource utilization rate of the own cell calculated in this way may be referred to as “virtual radio resource utilization rate”. Therefore, it can be said that the virtual radio resource utilization rate of the own cell is also the own cell utilization status.

Assuming that no retransmission occurs, the transmission time of data and ACK for the data is the usage time of the radio resource, so the radio resource usage rate ρ _{s, n} of the application _n is _expressed by the following equation: .
ρ _{s, n} = Σ {(transmission time of data frame of application n + time required for ACK of data frame of application n) / MT}
MT is a measurement period for calculating the radio resource utilization rate, and in this embodiment is the time length of the control slot. Also, Σ in the above equation is the sum for the data frame of application n transmitted during the MT period. Therefore, the above equation becomes as follows.
ρ _{s, n} = N _{DATA, n} × (D _{DATA, n} + D _{ACK, n} ) (1)

Here, N _{DATA, n} is the number of data frames transmitted by application n per unit time in the control slot, D _{DATA, n} is the average time required for transmission of data frames of application n, and D _{ACK, n} Is the time taken to ACK the data frame of application n. D _{ACK, n} is a time uniquely determined only by the transmission rate of ACK. N _{DATA, n} and D _{DATA, n in the} equation (1) are respectively _expressed by the following equations. Incidentally, _{O n} is an offered load of the application _{n (b / s), L} avg, n is the average packet size of the application n (Byte). In this simulation, for application packets exceeding the MTU size, the average IP packet size is assumed to be the MTU size. D _fixed is a physical layer overhead (preamble length) independent of the transmission rate, L _fixed is an overhead other than the physical layer dependent on the transmission rate, and R _n is a transmission rate (b / s).
_{N DATA, n = O n /} (L avg, n × 8)
D _{DATA, n} = D _fixed + (L _{avg, n} × 8 + L _fixed ) / R _n

Therefore, the radio resource utilization rate of equation (1) is as follows:
_{ρ s, n = coef n ×} O n / R n
However, coef _n is as follows.
coef _n = 1 + {(D _fixed + D _{ACK, n} ) × R _n + L _fixed } / (L _{avg, n} × 8)
Therefore, the radio resource utilization rate ρ _s of the own cell is as follows. Note that S is a set of all applications in the own cell that perform wireless communication in the control slot of interest.
_{ρ s = Σ n∈S {coef n} × O n / R n} (2)

In this manner, the own cell usage status, which is the radio resource usage rate, can be calculated from the offered load, transmission rate, and average packet size of each application. Therefore, the own cell usage status acquisition unit 21 can acquire the current usage status of the own cell (virtual radio resource usage rate of the own cell) as described above according to the offered load in the own cell. Note that from the 802.11g data frame format, D _fixed is 16 + 4 = 20 (μs), and L _fixed is {(2 + 24 + 8 + 20 + 8 + 4) × 8 + 6} = 534 (bit). Here, for simplification of description, the padding region is not considered.

  The other cell usage status acquisition unit 22 acquires the current usage status of another cell, which is the current radio resource usage status of another cell that may interfere with the own cell. This other cell current use situation may be the latest other cell use situation in another cell, or may be a new other cell use situation that can be identified with the latest other cell use situation. The other cell usage status is the usage status of radio resources of other cells. The other cell may be one cell or two or more cells. The other cell is an interference cell for the own cell, for example, another cell adjacent to the own cell. The other cell usage status acquisition unit 22 may acquire the other cell current usage status according to the carrier sense, or may receive the other cell current usage status from another device. When acquiring the other cell current usage status according to the carrier sense, the other cell usage status acquisition unit 22 is, for example, a period obtained by excluding the communication period of the own cell from the usage period of the radio resource obtained from the sensing result. May be used to calculate the current radio resource utilization rate and the current radio resource utilization time. The method for distinguishing the communication between the self and other cells in the sensing result is as described above. When acquiring the other cell current usage status using the sensing result, the other cell usage status acquisition unit 22 uses the radio resource usage status corresponding to both the own cell and the other cell (that is, all the radio resources). The other cell current usage status which is the radio resource usage status obtained by subtracting the current cell current usage status acquired by the own cell usage status acquisition unit 21 may be acquired from the usage status. When receiving the other cell current usage status from another device, for example, the radio communication device 1 that is a radio terminal device may receive the other cell current usage status from the radio base station.

The relational expression specifying unit 23 uses the current cell current usage status acquired by the local cell usage status acquisition unit 21 and the current usage status of other cells acquired by the other cell usage status acquisition unit 22, and uses the current cell usage status and the other cells. A relational expression indicating the relationship with the usage status is specified. The relational expression specifying unit 23 uses the current cell current use situation and the other cell current use situation acquired in a certain control slot, and uses the relational expression used in the prediction of the availability of radio communication in the next control slot. Will be identified. The relational expression indicating the relationship between the own cell usage status and the other cell usage status, which passes through the current cell current usage status and the other cell current usage status, changes according to the own cell current usage status and the other cell current usage status. is there. Specifically, the slope and intercept of the relational expression, which is a linear function, change according to the current use status of the own cell and the other cell current use status that are the starting points. Therefore, the relational expression specifying unit 23 specifies the relational expression indicating the relationship between the own cell use situation and the other cell use situation passing through both using the own cell current use situation and the other cell current use situation. . This relational expression is, for example, an expression showing a straight line extending from the lower left to the upper right in FIG. 3A. Note that FIG. 3A shows the radio resource utilization rates of the own cell and other cells as four patterns of 16%, 25%, 35%, and 45% when the offer load of the own cell is not present. It is the changed simulation result. For details, see Non-Patent Document 1 above. As described in Non-Patent Document 1, the relational expression is
y = a (x + c) (3)
Can be described. Note that x is the own cell usage status, y is the other cell usage status, c is a predetermined constant, and a is a coefficient determined by the own cell current usage status and the other cell current usage status. . Here, the coefficient a is normally a positive value. This is because it is considered that the collision of radio signals increases as the own cell usage status increases, and the usage status of other cells increases accordingly. From the above equation (3), when the current cell current usage status and the other cell current usage status are x _cur and y _cur , respectively, the relational expression specifying unit 23:
a = y _cur / (x _cur + c) (4)
As a result, the value of the coefficient a can be determined, and as a result, the relational expression (3) can be specified. Note that specifying the relational expression means that the relational expression only needs to be specified as a result. Therefore, in order to specify the relational expression, the relational expression specifying unit 23 may specify, for example, the coefficient a in the expression (3) or the expression (3) itself. Specifying the coefficient or the expression may be storing the coefficient or the like in a recording medium (not shown). As described in Non-Patent Document 1, for example, c = 80.45.

The prediction unit 24 uses the boundary information stored in a recording medium (not shown), the relational expression specified by the relational expression specifying unit 23, and the current cell current use status to make a prediction regarding whether or not wireless communication can be accommodated. As will be described later, the prediction unit 24 specifies the boundary information adjusted according to the determination result in the previous control slot, the current use status of the own cell and the other cell current use status acquired in the previous control slot. Using the relational expression thus obtained and the current usage status of the own cell acquired in the previous control slot, a prediction to be used for radio resource allocation in the current control slot is performed. The current control slot is the control slot next to the previous control slot. The prediction may be, for example, a prediction regarding availability of radio communication when the radio resource usage status of the own cell increases, or a prediction regarding availability of radio communication when the radio resource usage status of the own cell decreases. It may also be a prediction regarding whether or not radio communication can be accommodated when the radio resource utilization status of other cells increases or decreases. In the present embodiment, prediction regarding whether or not wireless communication can be accommodated when the radio resource utilization status of the own cell increases will be mainly described, and other predictions will be described later. Note that “accommodability” means whether all traffic to be transmitted can satisfy a desired transmission quality. In other words, if it can be accommodated, the desired transmission quality is satisfied in each traffic of wireless communication. On the other hand, when it cannot be accommodated, the desired transmission quality is not satisfied in at least one of the traffics of wireless communication. Next, boundary information will be described. In FIG. 3A, the own cell usage status (virtual radio resource usage rate of own cell) and other cell usage status (radio resource usage rate of other cells) when radio communication can be accommodated in the own cell are indicated by ○, □, etc. Plotting is performed, and the use state of the own cell and the use state of other cells when wireless communication cannot be accommodated in the own cell are plotted with x or-. For example, when the throughput is larger than the threshold according to the offered load, it can be stored, and otherwise it cannot be stored. The threshold according to the offered load may be, for example, the offered load itself or may be a value obtained by multiplying the offered load by a value close to 1. The boundary line A is a line indicating the boundary between the use situation (○ etc.) that can be accommodated and the use situation (× etc.) that cannot be accommodated. The information indicating the relationship between the own cell usage status and the other cell usage status corresponding to the boundary A is the boundary information. Therefore, as described above, when x is the own cell usage status and y is the other cell usage status, the equation corresponding to the boundary A is y = F (x) (5)
May be used as boundary information. The function F may be a linear function as shown in FIG. 3A. For example, when p and q are arbitrary real numbers, F (x) = px + q may be satisfied. That is,
y = px + q (6)
It may be. In such a case, the boundary information may be information indicating p and q. In the present embodiment, the case where the boundary information is a linear function will be mainly described. The boundary line A shown in FIG. 3A is expressed by the following equation (see Non-Patent Document 1 above).
y = −1.1 × x + 73.137 (7)

Here, a method of calculating the boundary line A will be briefly described. FIG. 3B plots the own cell usage status (the radio resource usage rate of the own cell) and the other cell usage status (the radio resource usage rate of the other cell) with ○ when the radio communication can be accommodated in the own cell. This is a simulation result in which the own cell usage status and the other cell usage status when wireless communication cannot be accommodated in the own cell are plotted with x. The boundary between the circles and the crosses becomes the accommodability boundary line. The algorithm for determining the boundary line does not matter. The boundary line may be set using a linear classifier that maximizes the margin, such as SVM (Support Vector Machine), or the boundary line may be set using other methods. The above equation (7) is obtained by calculating the boundary line A by SVM in the simulation result of FIG. 3B.
In addition, with respect to the boundary line A, the ◯ side may be referred to as an accommodable side, and the x side may be referred to as an unaccommodable side. In addition, with respect to the boundary line A, the region on the circle side may be referred to as an accommodable region, and the region on the x side may be referred to as an unaccommodable region.

In addition, the prediction unit 24 may perform prediction by directly using boundary information and relational expressions, or may perform prediction by using indirectly. The direct use means that the prediction unit 24 directly uses the boundary information itself or the relational expression itself for prediction. Indirect use means that the prediction unit 24 uses an equation according to boundary information or an equation according to a relational expression.
In addition, when the adjustment unit 27 adjusts the boundary information, the prediction unit 24 performs prediction using the adjusted boundary information. That is, the prediction unit 24 performs the prediction using the boundary line indicated by the expression (10) described later instead of the expressions (6) and (7).

  Prediction regarding whether or not the wireless communication can be accommodated by the prediction unit 24 includes prediction of whether or not additional wireless communication can be accommodated, how much wireless communication can be accommodated, and the like. Specifically, the prediction performed by the prediction unit 24 may be (A) prediction regarding whether or not wireless communication can be accommodated according to an additional offered load, and (B) wireless that can be additionally accommodated in the own cell. It may be a prediction related to communication, or may be another prediction related to availability of wireless communication when the radio resource usage status of the own cell increases. Hereinafter, the prediction of (A) and (B) will be described.

(A) Prediction regarding availability of wireless communication according to additional offered load The prediction unit 24 uses the own cell usage status after adding an additional offered load of wireless communication in the own cell, Whether or not wireless communication can be accommodated according to the loading may be determined. The additional offered road is an offered road to be added in the future. The additional offered load may be, for example, an offered load of an application that is not currently performing wireless communication but wants to start a new wireless communication, and an increase in applications that want to increase traffic over the current wireless communication. It may be an offered road in minutes. When the additional offered load is the offered load of the wireless communication apparatus 1, the prediction unit 24 may receive the additional offered load from the processing unit 13 or the like, for example. The prediction unit 24 may receive a transmission rate and a packet size from the processing unit 13 and the like together with the additional offered load. In addition, when the additional offered load is an offer load of another device belonging to the own cell, the prediction unit 24 obtains an additional offer load from another device via the communication unit 11, for example. You may receive it. The prediction unit 24 may also receive a transmission rate and a packet size from the other apparatus together with the additional offered load. Note that the transmission rate and the packet size are information necessary for calculating the radio resource utilization status from the offered load as described above. In addition, when there are two or more additional offered loads, prediction processing may be performed for each of them, prediction processing may be performed for those combined, or prediction for all combinations thereof. You may perform the process of.

  When receiving the additional offered load, the prediction unit 24 calculates the own cell usage state after adding the additional offered load. For example, when the current offered load of wireless communication in the own cell is known, the prediction unit 24 calculates the own cell usage status corresponding to the current offered load and the additional offered load. May be. In addition, the prediction unit 24 predicts the own cell usage status after adding the additional offered load, for example, by combining the current usage status of the own cell and the radio resource usage status corresponding to the additional offered load. May be. This own cell usage status is a usage status when it is assumed that there is no overload. Note that the predicted own cell usage status may be the result of simply adding the current usage status of the own cell and the radio resource usage status corresponding to the additional offered load, or not. In the latter case, interference that increases by performing wireless communication according to an additional offered load may be considered. In that case, the predicted own cell usage situation after adding an additional offered load is usually larger than the result of simply adding the two.

When the prediction unit 24 obtains the own cell usage situation after adding the additional offered load, the other cell usage situation corresponding to the own cell usage situation is determined using the relational expression specified by the relational expression specifying unit 23. calculate. Specifically, if the own cell usage status after adding an additional offered load is x1, by using the above equations (3) and (4), the additional offered load is It is possible to calculate the other cell usage status y1 according to the above.
y1 = a (x1 + c) (8)
= _Ycur (x1 + c) / ( _xcur + c)

Accordingly, the predicting unit 24 determines whether the own cell usage status x1 and the other cell usage status y1 after adding the additional offered load exist on the accommodable side of the boundary indicated by the boundary information, or cannot be accommodated. Whether it can be accommodated or not can be determined depending on whether it is present on the side. That is, when x1 and y1 exist on the accommodable side, radio communication corresponding to the additional offered load can be accommodated. When x1 and y1 exist on the accommodable side, the additional offer Wireless communication according to the loading cannot be accommodated. In this case, the relational expression is directly used. For example, the prediction unit 24
a (x1 + c) -F (x1) (9)
= _Ycur (x1 + c) / ( _xcur + c) -F (x1)
If the result is a negative value, it can be determined that it can be accommodated, and if the result is a positive value, it can be determined that it cannot be accommodated. In this case, the prediction unit 24 can indirectly use boundary information and relational expressions. In addition, when the result is 0, you may judge that it can accommodate, or you may judge that it cannot accommodate. The determination result may be stored in a recording medium (not shown).

(B) Prediction regarding radio communication that can be additionally accommodated in own cell The prediction unit 24 may acquire a radio resource usage status corresponding to radio communication that can be additionally accommodated in the own cell. And the prediction part 24 may acquire the addable information which is the information regarding the radio | wireless communication which can be additionally accommodated in the own cell using the acquired radio | wireless resource utilization condition. The addable information may be the radio resource usage status corresponding to the radio communication that can be additionally accommodated, and the radio resource usage status may be added to the offered load or other information (for example, added to the own cell). Or the number of wireless terminal devices that can be accommodated). As will be described later, if the transmission rate and the packet size are known, the radio resource usage status can be converted into an offered load. Therefore, the prediction unit 24 uses the radio resource usage status, the transmission rate, and the like to provide the offered load. It is also possible to acquire addable information. Since the boundary indicated by the boundary information indicates the accommodation limit, the radio resource usage situation that can be accommodated in addition to the current radio resource usage situation by obtaining the intersection of the equations (3) and (5) Can be obtained. Specifically, the prediction unit 24 acquires the own cell usage status at the intersection of the relational expression specified by the relational expression specifying unit 23 and the boundary indicated by the boundary information. Then, a value obtained by subtracting the own cell current use status acquired by the own cell use status acquisition unit 21 from the own cell use status becomes a radio resource use status corresponding to radio communication that can be additionally accommodated in the own cell. . In addition, considering the increase of interference according to the increase of radio resource usage in the own cell, than the result of subtracting the current usage status of the own cell from the own cell usage status according to the intersection of the relational expression and the boundary A small value may be used as a radio resource usage status corresponding to radio communication that can be additionally accommodated. Further, as described above, the prediction unit 24 may or may not convert the radio resource usage status into an offered load or the like. When converting the radio resource usage status into offered load, for example, the above equation (2) may be used. For the transmission rate and packet size required for the conversion, an offered load may be calculated as a guide using an average one. The addable information predicted by the prediction unit 24 may be stored in a recording medium (not shown).

  Note that the prediction result by the prediction unit 24 may be used in the wireless communication device 1 or may be used in another device. In the latter case, for example, the prediction result may be transmitted to another device via the communication unit 11. The transmission destination device may be a radio base station or a radio terminal device in the own cell. For example, when the wireless communication device 1 is a wireless base station, the addable information predicted by the prediction unit 24 may be included in a beacon transmitted by the wireless communication device 1 that is the wireless base station and transmitted. It may be transmitted by other methods.

  When the radio resource allocation of the own cell is changed so that the range is predicted to be accomodable by the prediction unit 24, the determination unit 25 determines whether the radio communication can be accommodated in the own cell after the change. To do. That is, when the own cell usage status and the other cell usage status are changed on the accommodable side with respect to the boundary line, the determination unit 25 determines whether the changed wireless communication can be accommodated in the own cell. Become. The radio resource may be allocated by the radio communication device 1 or another device as long as the radio resource is allocated according to the prediction result. Also, the change in the allocation of the radio resource is made so that the radio resource usage status of the own cell after the change and the radio resource usage status of the other cell are closer to the boundary line than before the change in the accommodable area. It may be a change. The change may be performed, for example, by control by which the control unit 12 allocates radio resources so that the maximum radio resources are used in the accommodable area. Also, for example, when radio resource allocation in the current control slot is performed according to a prediction result using the current cell current usage status of the previous control slot, the determination unit 25 performs radio communication in the current cell in the current control slot. To determine whether or not For example, the determination unit 25 may make the determination using the observation result of the wireless communication, or may make the determination using the determination result by the user. In the former case, for example, the determination unit 25 may determine that it was able to be accommodated when the throughput is larger than the threshold value according to the offered load, and may determine that it was not able to be accommodated otherwise. The threshold according to the offered load may be, for example, the offered load itself, or may be a value obtained by multiplying the offered load by a value close to 1 (for example, 0.98). Further, when using the determination result by the user, for example, when the user inputs that the communication quality is good, the determination unit 25 determines that the communication is good, and inputs that the communication quality is not good. It may be determined that it could not be accommodated. In addition, when there is no input that the communication quality is not good from the user, it may be considered that there is an input that the communication quality is good. Further, when the wireless communication apparatus 1 performs wireless communication using a plurality of applications, the determination unit 25 may determine whether the wireless communication can be accommodated in the own cell for each application. In this case, the determination unit 25 may determine that wireless communication could not be accommodated in the own cell when there is even one application that could not accommodate wireless communication. The determination unit 25 may store the determination result on a recording medium (not shown). Further, when the determination is performed using the wireless communication throughput, the determination unit 25 may estimate the throughput of each traffic in the own cell and use the estimated throughput.

  The history information accumulation unit 26 accumulates history information including at least past determination results by the determination unit 25 in a recording medium (not shown). The recording medium is, for example, a semiconductor memory, an optical disk, a magnetic disk, or the like, and may be included in the history information storage unit 26 or may exist outside the history information storage unit 26. Further, this recording medium may or may not store the history information temporarily. The history information may be, for example, a past determination result, information including a past determination result and a communication status in the own cell at the time of the determination, or other information (for example, , Information indicating whether adjustment according to the determination result has been made, or the like). The communication status may be, for example, offered load, transmission rate, throughput, radio resource usage status, or the like. The communication status may be acquired for each application.

The adjustment unit 27 adjusts the boundary information according to the determination result by the determination unit 25. The adjustment unit 27 adjusts the boundary information using the determination result determined for the previous control slot. The boundary information is used for prediction of the current control slot (prediction using the current use status of the own cell of the previous control slot). The adjustment unit 27 may adjust the boundary information so that the area that cannot be accommodated increases when the determination unit 25 determines that the wireless communication cannot be accommodated in the own cell. The adjustment unit 27 may adjust the boundary information so that the area that can be accommodated increases when the determination unit 25 determines that the wireless communication can be accommodated in the own cell. For the adjustment, for example, the above equation (6)
y = px + q-M (10)
And may be performed by changing M. M is a margin for moving the boundary line up and down. The larger the M, the smaller the accommodating area, and the smaller M, the larger the accommodating area. Thus, the adjustment of the boundary information performed by the adjustment unit 27 may be to change the intercept without changing the inclination of the boundary line. The boundary information adjusted by the adjustment unit 27 may be stored in a recording medium (not shown). Further, as will be described later, the margin M may be set with an upper limit or a lower limit, or may not be so.

  The adjustment will be described with reference to FIGS. 4A and 4B. In FIG. 4A, it is assumed that the current cell current usage status and the other cell current usage status at the time when the prediction by the prediction unit 24 is performed are at the position P1. Then, it is assumed that when the predicting unit 24 increases the number of applications that perform wireless communication by one to three, the own cell usage status and the other cell usage status are predicted to be positions P2 to P4, respectively. Then, it is assumed that radio resources are allocated by the control unit 12 to increase the number of applications that perform radio communication by two. Thereafter, if it is determined by the determination unit 25 that wireless communication could not be accommodated, the boundary line is a little more accommodable side. Therefore, the adjustment unit 27 may adjust the boundary information so that the boundary line is located at the boundary line CO1 in FIG. 4B. On the other hand, if it is determined by the determination unit 25 that the wireless communication can be accommodated, the boundary line may have been a little more unacceptable. Therefore, the adjustment unit 27 may adjust the boundary information so that the boundary line is located at the boundary line CO2 in FIG. 4B. As described above, the boundary line can be adjusted to an appropriate position according to the state of the wireless communication by adjusting the boundary line depending on whether or not the wireless communication is accommodated according to the radio resource allocation using the prediction result. Become. Hereinafter, each of the case where adjustment is performed so as to increase the unaccommodable area and the case where adjustment is performed so that the unaccommodable area is decreased will be described in more detail.

(I) Adjustment in which the unaccommodable area increases The adjustment unit 27 decreases the intercept of the boundary line by ΔM ₊ (> 0), for example, when the determination unit 25 determines that wireless communication could not be accommodated in the own cell. You may let them. That is, when it is determined by the determination unit 25 that wireless communication could not be accommodated in the own cell, the adjustment unit 27 may set M _next which is a margin M used in the next control as the following equation. Note that M _cur is a margin M before adjustment, ΔM ₊ is a margin increment in one adjustment, and M _max is a maximum value of the margin M.
M _next = min ((M _cur + ΔM ₊ ), M _max )

In addition, when the determination unit 25 determines that the wireless communication cannot be accommodated in the own cell, the adjustment unit 27 increases as the number of applications determined as unacceptable increases. The boundary information may be adjusted as described above. That is, when it is determined by the determination unit 25 that the wireless communication cannot be accommodated in the own cell, the adjustment unit 27 may set the margin M _next used in the _next control as the following equation. Note that N _NG is the number of applications that are determined to be _unacceptable in the own cell, and N _Tx is the number of applications that performed wireless communication in the own cell. In this case, the maximum value of the margin increment in one adjustment is ΔM ₊ .
M _next = min ((M _cur + N _NG × ΔM ₊ / N _Tx ), M _max ) (11)

  It can be considered that the larger the number of applications that do not satisfy the desired transmission quality, the more the current boundary line deviates from the ideal boundary line. Therefore, as shown in the above equation, it is considered that the boundary line can be converged more quickly to the original boundary line position by increasing the margin increment as the number of applications that do not satisfy the desired transmission quality increases.

(II) Adjustment to reduce unacceptable area The adjustment unit 27 increases the intercept of the boundary line by ΔM ₋ (> 0), for example, when the determination unit 25 determines that the wireless communication can be accommodated in the own cell. May be. That is, when the determination unit 25 determines that the wireless communication can be accommodated in the own cell, the adjustment unit 27 may set the margin M _next used in the _next control as the following equation. ΔM ₋ is a margin reduction amount in one adjustment, and M _min is a minimum value of the margin M.
M _next = max ((M _cur −ΔM ₋ ), M _min ) (12)

In addition, the adjustment unit 27 determines that the wireless communication has been accommodated in the own cell by the determination unit 25 and changes the radio resource allocation in the own cell so that the own cell usage state predicted by the prediction unit 24 is obtained. When the current cell usage status and other cell current usage status after being generated are within a predetermined range from the own cell usage status and other cell usage status predicted by the prediction unit 24, it can be accommodated as described above. The boundary information that increases the area may be adjusted. In other words, the prediction unit 24 predicts that the own cell usage status after adding the additional offered load is x1, and the other cell usage status corresponding to the additional offered load is y1, and the additional offer When the own cell current usage status and the other cell current usage status after the control for adding the load is performed by the control unit 12 are x _cur , y _cur , (x _cur , y _cur ) is ( When the distance is within a predetermined range from x1, y1), the adjustment unit 27 may perform the above-described adjustment. Note that (x _cur , y _cur ) is acquired in the same control slot as the control slot used to acquire the determination result used by the adjustment unit 27 for adjustment. Within the predetermined range, for example, as shown in FIG. 5A, when P5 (x _cur , y _cur ) is within a region RA1 of a circle having a radius TH1 centered on P3 (x1, y1), that is, ,
{(X _cur −x1) ² + (y _cur −y1) ² } ^1/2 <TH1 (Condition 1)
It may be the case. Further, for example, as shown in FIG. 5B, the predetermined range is a case where P5 (x _cur , y _cur ) is within a square area RA2 whose side is TH2 with P3 (x1, y1) as the center. That is,
| X _cur −x1 | <TH2 / 2 and | y _cur −y1 | <TH2 / 2 (Condition 2)
It may be the case. Further, the predetermined range may be a range other than those. Here, when the determination using Condition 1 or Condition 2 is performed, the prediction unit 24 may predict x1 and y1. That is, using the relational expression, the prediction unit 24 uses the own cell in accordance with a change in radio resource allocation of the own cell in a range that can be accommodated (for example, start of radio communication according to an additional offered load). The situation (x1) and the other cell usage situation (y1) may be predicted. In this case, when the allocation of the radio resource of the own cell is changed so that the own cell usage status (x1) predicted by the prediction unit 24 is obtained, the determination unit 25 performs radio transmission in the own cell after the change. It may be determined whether communication has been accommodated. Whether or not to adjust the boundary information is determined according to the determination result and whether or not Condition 1 or Condition 2 is satisfied. In addition, it can be said that the case where the condition 1 is satisfied or the case where the condition 2 is satisfied is a case where the estimation accuracy of the radio resource utilization status is high.

In addition, when the own cell usage status or the other cell usage status exists in an accommodable area away from the boundary line, it is considered that the adjustment of (II) is not appropriate. Therefore, the adjustment unit 27 may perform the adjustment (II) only when the distance between (x _cur , y _cur ) and the boundary line is smaller than a predetermined threshold.
Further, the relationship between ΔM ₊ and ΔM ₋ is not limited, but may be, for example, ΔM ₊ > ΔM ₋ . It is considered necessary to move the boundary line to the accommodable area side if it cannot be accommodated. However, if it can be accommodated, it is not always necessary to move the boundary line to the unaccommodable area side. It is possible.

  Note that the adjustment unit 27 predicts that the determination result according to the adjusted boundary information cannot accommodate wireless communication in the own cell using the history information accumulated by the history information accumulation unit 26. However, the boundary information need not be adjusted. Note that when the adjustment unit 27 determines not to adjust the boundary information, the adjustment unit 27 may not adjust the boundary information only at that time, or may not adjust the boundary information for a predetermined period from that point. Also good. In the following description, the determination result that the wireless communication can be accommodated in the own cell is referred to as “OK”, and the determination result that the wireless communication cannot be accommodated in the own cell is referred to as “NG”.

  First, a case where only judgment results are included in the history information will be described. In that case, it is predicted that the next judgment result of the arrangement is NG when the arrangement of the judgment results for the most recent predetermined period or the predetermined number of times satisfies a predetermined condition or from the history information. Sometimes, the adjustment unit 27 does not have to perform adjustment. In the former case, for example, when the arrangement of the determination results for the most recent predetermined period or the predetermined number of times is NG → OK → NG → OK, the adjustment unit 27 may not perform adjustment. In such a case, it is an ideal boundary line at the time of OK, and since the accommodating area is wider than the ideal boundary line at the time of NG, NG and OK are repeated. It is thought that there is. Therefore, it is considered preferable not to adjust the boundary information for a predetermined period. Moreover, as a case where it is predicted from the history information that the next determination result of the arrangement is NG, for example, the arrangement of the determination results for the most recent predetermined period or the predetermined number of times is NG → OK → NG → OK, When the previous history information includes NG → OK → NG → OK → NG more than a predetermined number of times, the adjustment unit 27 does not need to adjust. In such a case, there is a high possibility that the next determination result is determined to be NG from the history information, so it is considered preferable not to adjust the boundary information for a predetermined period. Note that the determination result used for the determination may be a determination result in which the boundary information is adjusted according to the determination result. In this case, the history information may include a determination result and information indicating whether adjustment according to the determination result has been performed.

  Next, the case where the history information includes the determination result and the communication status in the own cell at the time of the determination will be described. In that case, the adjustment unit 27 determines whether the determination result corresponding to the same past communication status as the current communication status is OK or NG using the most recent predetermined period or a predetermined number of history information. Then, the adjustment unit 27 may perform the adjustment when the determination result is OK, and may not perform the adjustment when the determination result is NG. The past communication status that is the same as the current communication status may be a past communication status that is exactly the same as the current communication status, or may be the same as the current communication status within a predetermined error range. It may be a past communication situation. If there is no past communication status that is the same as the current communication status, the adjustment unit 27 may perform adjustment. In addition, the adjustment unit 27 determines the current communication status used in the determination, for example, via the route (not shown), the communication unit 11, the control unit 12, the own cell usage status acquisition unit 21, the other cell usage status acquisition unit 22, etc. May be obtained from

  Here, timings for acquiring the radio resource usage status, predicting whether radio communication can be accommodated, determining whether the radio communication is successful, and adjusting boundary information will be described together. When acquisition of the current usage status of the own cell and the current usage status of another cell is performed in a certain control slot (previous control slot), the availability is predicted accordingly. Then, in the next control slot (current control slot), the radio resource allocation is controlled according to the prediction result, and the success or failure of the accommodation is determined according to the control. Then, using the determination result of the current control slot, the boundary information used for prediction in the next control slot (next control slot) is adjusted. In addition, since these processes are executed in parallel, in the current control slot, the boundary information adjusted according to the determination result of the previous control slot and the current use status of the own cell acquired in the previous control slot Radio resource allocation is performed according to the prediction result of accommodation availability using the, and the acquisition of the determination result used to acquire the prediction result used in the radio resource allocation in the next control slot; Acquisition of the current use status of the own cell is performed.

  The communication unit 11 performs wireless communication via an antenna. Any wireless communication performed by the communication unit 11 may be used. The wireless communication may be, for example, wireless LAN communication, other mobile communication, or other wireless communication. The wireless communication performed by the communication unit 11 is usually wireless communication in an autonomous distributed wireless communication system. In the present embodiment, as described above, the case where the wireless communication is communication using a wireless LAN will be mainly described. When receiving an offered load or the like from a communication destination wireless base station or wireless terminal device, the communication unit 11 may store the received information in a recording medium (not shown). Note that the communication unit 11 may or may not include a wireless communication device (for example, a network card) for performing wireless communication. The communication unit 11 may be realized by hardware, or may be realized by software such as a driver that drives a communication device.

  The control unit 12 controls transmission by the communication unit 11 according to the result of carrier sense using the communication unit 11. Specifically, the control unit 12 determines whether or not wireless communication is performed on the transmission path according to the result of carrier sense, and when the wireless communication is not performed, the communication unit 11 performs transmission. May be controlled. Moreover, the control part 12 may specify the frequency which is vacant according to the result of a carrier sense, and may control the communication part 11 so that it may transmit with the specified frequency. The control by the control unit 12 may be, for example, CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance) control or CSMA / CD (Carrier Sense Multiple Access / Collision Detection) control. In the present embodiment, the former case will be mainly described. Note that it is already known to control communication according to the result of carrier sense, and a detailed description thereof will be omitted.

  Further, the control unit 12 may control allocation of radio resources related to radio communication performed by the communication unit 11 according to the prediction result by the prediction unit 24. Note that the control unit 12 controls radio resource allocation in the current control slot in accordance with a prediction result using the current cell current usage status acquired in the previous control slot. For example, when a certain application wants to start wireless communication, the control is performed so that the wireless communication can be started or the wireless communication cannot be started according to the prediction result by the prediction unit 24. It may be to do. For example, when a certain application wants to perform wireless communication with a desired offered load, and the prediction result by the prediction unit 24 is predicted to be unable to accommodate the offered load, the control unit 12 You may control not to perform the wireless communication by the application. On the other hand, when a certain application wants to perform wireless communication with a desired offered load and it is predicted that the offered load can be accommodated by the prediction result by the prediction unit 24, the control unit 12 You may control so that wireless communication by an application can be performed. In addition, for example, when a certain application wants to start wireless communication, the control by the control unit 12 may pass to the application whether or not the wireless communication can be accommodated according to the prediction result. Further, as described above, the control unit 12 may change the allocation of radio resources of the own cell so that the range predicted to be accomodable by the prediction unit 24 is obtained. The change may be, for example, control for allocating radio resources so that the maximum radio resources are used in the accommodable area. Specifically, using the prediction result, among the combinations of applications that can be accommodated, the combination with the most operational applications may be selected, or the combination that includes the application with the highest priority may be selected. Good. Then, channel access may be permitted for applications included in the selected combination, and channel access may be stopped for other applications.

  Further, the control unit 12 may control the change of the radio network topology according to the prediction result by the prediction unit 24. The change of the wireless network topology may be one or more selected from a change of a communication destination of wireless communication performed by the communication unit 11 and a change of a communication destination of wireless communication performed by another device. For example, when the prediction result indicates that wireless communication according to the offered load cannot be accommodated and the wireless communication device 1 is a wireless terminal device, the control unit 12 performs the communication unit 11. You may change the wireless base station which is a communication destination of wireless communication. The change may be, for example, changing to a radio base station that is less congested. For example, if the beacon transmitted by the wireless base station includes information corresponding to the number of wireless terminal devices that are communicating via the wireless base station, the degree of congestion is used. Or may be determined by sensing. Further, for example, when the prediction result indicates that the wireless communication according to the offered load cannot be accommodated, and the wireless communication device 1 is a wireless base station, the control unit 12 An instruction may be transmitted from the wireless communication apparatus 1 to another wireless base station so as to change the wireless base station that is the communication destination of the wireless communication performed by the wireless terminal apparatus to another wireless base station. In response to the instruction, the wireless terminal device that is the communication destination of the communication unit 11 may change the wireless base station that is the wireless communication destination from the wireless communication device 1 to another wireless base station.

  The processing unit 13 performs processing related to received information and transmitted information. The processing unit 13 may perform the processing for each application. For example, when voice communication is performed, the processing unit 13 accumulates packets corresponding to the audio signal received from the application in a transmission queue (not shown), or packets corresponding to the voice communication received by the communication unit 11. May be received and passed to the application. Note that packets queued in the transmission queue are transmitted by the communication unit 11. Further, when queuing can be performed for each application in the transmission queue, the processing unit 13 may accumulate packets in the transmission queue for each application.

  Note that information used to acquire the current usage status of the own cell, the current usage status of other cells, and the like, for example, the latest sensing result may be stored in a recording medium (not shown). In this case, for example, the self-other cell may be specified for each wireless communication period in order to distinguish the self-other cell.

Next, operation | movement of the accommodation prediction apparatus 2 is demonstrated using the flowchart of FIG.
(Step S <b> 101) The prediction unit 24 determines whether or not to perform prediction regarding the accommodation possibility. And when performing prediction, it progresses to step S102, and when that is not right, it progresses to step S106. For example, the prediction unit 24 may determine to perform prediction when a certain control slot ends, or may determine to perform prediction at another timing.

  (Step S102) The own cell usage status acquisition unit 21 acquires the current usage status of the own cell of a certain control slot.

  (Step S103) The other cell usage status acquisition unit 22 acquires the other cell current usage status of the same control slot from which the current cell current usage status is acquired in step S102.

  (Step S104) The relational expression specifying unit 23 specifies a relational expression corresponding to the current use situation of the own cell acquired in step S102 and the current use situation of other cells acquired in step S103.

  (Step S105) The prediction unit 24 uses the current cell current usage status acquired in step S102, the relational expression specified in step S104, and the boundary indicated by the boundary information to determine the radio resource usage status of the own cell. A prediction is made regarding the possibility of accommodating wireless communication in the case of an increase. Then, the process returns to step S101.

  (Step S106) The determination unit 25 determines whether or not to determine whether or not wireless communication can be accommodated in the own cell. If it is determined whether or not the accommodation is successful, the process proceeds to step S107. If not, the process returns to step S101. The determination unit 25 may determine, for example, that when a certain control slot is finished, it may determine whether the accommodation is successful or not for wireless communication in the control slot, and may determine that the accommodation is successful at other timings. Also good. In addition, in order to perform prediction using boundary information adjusted according to the determination result, the determination of the success or failure of the radio communication in a certain control slot is based on the current cell current usage status acquired in that control slot. It is preferable to be performed before the prediction using the above.

  (Step S107) The determination unit 25 determines whether or not wireless communication can be accommodated in the own cell.

  (Step S108) The adjustment unit 27 determines whether or not to perform the next adjustment by using the determination result in step S107 and the history information. If the adjustment is to be performed, the process proceeds to step S109. If not, the process returns to step S101.

  (Step S109) The history information storage unit 26 adds the determination result in step S107 to the history information.

  (Step S110) If it is determined in step S107 that it has been accommodated, the process proceeds to step S111. If not, the process proceeds to step S113.

(Step S111) The adjustment unit 27 determines whether a condition for changing the boundary information is satisfied. If the condition is satisfied, the process proceeds to step S112. If not, the process returns to step S101. For example, when x _cur , y _cur , x1, y1 satisfies the above-described condition 1, the adjustment unit 27 may determine that the condition is satisfied, and x _cur , y _cur , x1 , Y1 may satisfy the condition 2 described above, it may be determined that the condition is satisfied.

  (Step S112) The adjustment unit 27 adjusts the boundary information so that the accommodable area increases. Then, the process returns to step S101.

  (Step S113) The adjustment unit 27 adjusts the boundary information so that the unaccommodable area increases. Then, the process returns to step S101.

  In the flowchart of FIG. 2, operations related to the components other than the accommodation prediction device 2 in the wireless communication device 1 are omitted. However, for example, the wireless communication is appropriately performed by the communication unit 11, the control unit 12, and the processing unit 13. Shall be done. In addition, the control unit 12 may perform allocation of radio resources in radio communication, change of the topology of the radio network, and the like using the prediction result. In the flowchart of FIG. 2, the case where the determination result is added to the history information only when adjustment is performed has been described, but this need not be the case. Regardless of whether adjustment is performed, the determination result may be added to the history information. In that case, information indicating whether or not adjustment has been performed may be added to the history information along with the determination result, or may not be. Moreover, although the case where the past determination result is included in the history information has been described, as described above, the history information may include the past determination result and the communication status at the time of the determination. When the history information includes the past determination result and the communication status at the time of the determination, the adjustment unit 27 determines in step S108 the history information including the communication status and the communication status at that time. May be used to determine whether to perform adjustment according to the determination result. 2 may be acquired separately from the processes included in the flowchart of FIG. 2 (for example, sensing results and information used for acquiring the throughput). Good. In the flowchart of FIG. 2, the process is ended by power-off or a process end interrupt.

Next, simulation results comparing conventional wireless LAN communication, wireless LAN communication using a fixed boundary line, and wireless LAN communication using an adjustment boundary line according to the present embodiment will be described. In the wireless LAN communication using the adjustment boundary line according to the present embodiment, control using history information is not performed. The system specifications used in the simulation are as follows.
Simulation time: 10.1 (seconds)
Number of trials: 10 times Area size: 20 (m) x 20 (m)
Sampling rate: 120 MHz
Center frequency: 2.442 GHz
Number of cells in area: 2 cells (own cell, other cells)
Traffic: Uplink (UL) only (constant bit rate)
Control slot length: 1 (second)
RTS / CTS: Not used Transmission power: 16 dBm (AP), 12 dBm (STA)
Number of antennas: 2 (AP), 1 (STA)
Antenna gain: 2.15 dBi
Transmission frame: DATA, ACK
Noise parameters: 300K, NF: 10dB
Sensing threshold: -88 dBm / 1.25 MHz

In the simulation, Expressions (11), (12), and Condition 1 were used for adjusting the boundary information. In addition, the parameter setting in (11) Formula, (12) Formula, and Condition 1 was performed as follows.
M _max : 20 (%)
M _min : -20 (%)
ΔM ₊ : 20 (%)
ΔM ₋ : 5 (%)
TH1: 20 (%)

  In the simulation, an IEEE802.11g ERP-OFDM based PHY-MAC cross-layer simulation was performed. Of the two BSSs (BSS1, BSS2) operated on the same frequency channel provided in an area of 20 (m) × 20 (m), BSS1 is set as the own cell and BSS2 is set as another cell. The BSS 1 also performs conventional wireless LAN communication (conventional example), wireless LAN communication using a fixed boundary line (fixed boundary line), and wireless LAN communication using an adjustment boundary line according to this embodiment ( (Adjustment boundary line). On the other hand, BSS2 is fixed to conventional wireless LAN communication. Here, the application to be operated is different for each BSS, but in the BSS, all STAs operate the same application. Also, the requirement QoE (Quality of Experience) achievement condition, that is, the condition for judging that accommodation is possible in the accommodation possibility determination is “achieving 98% throughput with respect to the applied traffic amount” as in the case of Non-Patent Document 1. did.

The radio resource utilization status was measured at the AP by power detection using FFT. The amount of traffic applied by each application and the transmission rate used in each wireless link are known, and the QoE satisfaction status and channel access availability for each STA are ideally transmitted. In this simulation, simulations were performed for two types of evaluation cases with different physical transmission rates and applied traffic amounts. The parameters for each case are as follows.
[Case 1]
Number of STAs per BSS: 6
Physical transmission rate: 24Mb / s
Payload length: 1000 bytes
Offer load per STA for BSS1: 300 kBytes / s
Offer load per STA of BSS2: 100 kBytes / s
Total offered load of BSS1: 1.8 Mbytes / s
Total offered load of BSS2: 0.6 MBytes / s
[Case 2]
Number of STAs per BSS: 6
Physical transmission rate: 6Mb / s
Payload length: 500 bytes
Offer load per STA for BSS1: 100 kBytes / s
Offer load per STA of BSS2: 25 kBytes / s
Total offered load of BSS1: 0.6 MBytes / s
Total offered load of BSS2: 0.15 Mbytes / s

  In each case, each STA in the own cell (BSS1) was given 3 to 4 times the amount of applied traffic as compared to the STA in the other cell (BSS2). Accordingly, the own cell is more strict in satisfying the requirement QoE than other cells.

  The simulation result of case 1 is shown in FIGS. 6A and 6B, and the simulation result of case 2 is shown in FIGS. 6C and 6D. 6A and 6C show the access permission rate and the required QoE satisfaction rate characteristics, and FIGS. 6B and 6D show the total throughput and the throughput of the application that satisfies the required QoE (hereinafter referred to as “requested QoE sufficient throughput”). ). The conventional example, fixed boundary line, and adjustment boundary line in FIGS. 6A to 6D are, as described above, the own cell (BSS1) as the conventional example (access permission rate is always 1), fixed boundary line, and adjustment boundary line, respectively. Is the result of the case. The other cells (BSS2) are all conventional examples as described above.

  In the conventional example of Case 1, although the total throughput is high, the required QoE satisfaction rate of the own cell is significantly low, about 0.3. On the other hand, at the fixed boundary line and the adjustment boundary line, the requested QoE satisfaction rate of the own cell is increased by stopping transmission of applications that cannot satisfy the requested QoE (that is, transmission of applications that cannot be accommodated). In particular, at the adjustment boundary line, the required QoE satisfaction rate and the required QoE satisfaction throughput of the own cell are higher than the fixed boundary line.

  In Case 2, the network is overloaded as in Case 1, but also in Case 2, the required QoE satisfaction rate and required QoE satisfaction throughput of the adjustment boundary in the own cell are higher than those in the conventional example and the fixed boundary. It has become.

  Therefore, in the adjustment boundary line (communication method according to the present embodiment), even in a conventional example in which control using the boundary line is not performed in an overload state, even for a fixed boundary line that does not adjust the boundary line, It turns out that it can accommodate more wireless communications.

  Next, the operation of radio communication apparatus 1 according to the present embodiment will be described using a specific example. In this specific example, the wireless communication device 1 is a wireless base station, and predicts whether or not an offer load can be accommodated in response to a request from a wireless terminal device. It is assumed that the wireless communication device 1 that is a wireless base station receives and stores the latest offered load related to an application during wireless communication from each application of each wireless terminal device in its own cell. Further, in this specific example, processing using history information is omitted for the sake of simplicity.

  Since a wireless terminal device existing in a cell of the wireless communication device 1 starts VoIP wireless communication, an offer load U (Mb / s) related to the VoIP wireless communication and a transmission rate used for the VoIP wireless communication It is assumed that R (Mb / s) and average packet size L (Byte) and a request for determining the availability of the offered load are transmitted to the wireless communication apparatus 1. Then, the information is received by the communication unit 11 and passed to the processing unit 13. Then, the processing unit 13 passes the offered load and the like to the prediction unit 24. In addition, it is assumed that the same offered load or the like is transmitted from the other wireless terminal device to the wireless communication device 1 and passed to the prediction unit 24.

  When a certain control slot ends, the prediction unit 24 determines that it is time to perform prediction, and passes an instruction to acquire the current use status of the own cell to the own cell use status acquisition unit 21 to acquire the other cell use status. An instruction to acquire the current usage status of other cells is given to the unit 22 (step S101). Upon receiving an instruction to acquire the current usage status of the own cell, the own cell usage status acquisition unit 21 stores the offered load in the latest control slot stored in the radio communication device 1 and the transmission rate of the radio communication. Then, the current use status of the own cell in the control slot is calculated by the equation (2) using the packet size and passed to the relational expression specifying unit 23 and the prediction unit 24 (step S102). Further, the other cell usage status acquisition unit 22 acquires the other cell current usage status, which is the latest radio resource usage rate of the other cell, using the sensing result in the latest control slot, and passes it to the relational expression specifying unit 23 ( Step S103).

  Upon receiving the current usage status of the own cell and the current usage status of other cells, the relational expression specifying unit 23 substitutes them into the equation (4), calculates the coefficient a, and passes it to the prediction unit 24 (step S104). Upon receiving the current use status of the own cell and the coefficient a, the prediction unit 24 adds the additional offered load U (Mb / s), the transmission rate R (Mb / s) used in the wireless communication, and the average packet size L. (Byte) is used to calculate the radio resource usage status of the own cell corresponding to the additional offered load. Also, for additional offered loads received from other wireless terminal devices, the wireless resource usage status of the own cell corresponding to the additional offered load is calculated. Then, the prediction unit 24 adds the radio resource usage status of the additional offered load and the current usage status of the own cell for all combinations of the additional offered loads, and the own cell usage status after the addition of the offered load. To get. And the prediction part 24 calculates the value of (9) Formula by substituting them. In this specific example, it is assumed that the value of the expression (9) is negative for all combinations of additional offered loads. Then, the prediction unit 24 determines that all additional offered loads can be accommodated, and passes the prediction result to the processing unit 13 (step S105). When the prediction result is received, the control unit 12 transmits a message indicating that wireless communication may be performed to each wireless terminal device that is a transmission source such as offered load. Those wireless terminal devices can know that wireless communication according to the offered load can be accommodated, and start wireless communication such as VoIP.

  Thereafter, the determination unit 25 compares the offered load with the throughput for each wireless communication including the additional offered load, and determines whether or not each wireless communication is accommodated (steps S106 and S107). As a result of the determination, the throughput of one application is smaller than 98% of the offered load, so it is assumed that the determination unit 25 determines that it cannot be accommodated (step S110). Then, the adjustment unit 27 changes the boundary information so that the unaccommodable area increases, and in the subsequent control slot, prediction using the changed boundary information is performed (step S113). In this way, boundary information is appropriately adjusted according to the determination result, so that it is possible to avoid not permitting start of wireless communication that can be accommodated or permitting wireless communication that cannot be accommodated. .

  In this specific example, the process from acquisition of the current cell current usage status etc. to the adjustment of the boundary information has been explained in order, but as described above, strictly speaking, the current cell current usage status in one control slot. Etc., acquisition processing, judgment processing, etc. are performed in parallel.

  In this specific example, the case where the wireless communication device 1 is a wireless base station has been described. However, when the wireless communication device 1 is a wireless terminal device, the prediction regarding the possibility of accommodating wireless communication is similarly performed. It can be carried out. In addition, when the wireless communication device 1 is a wireless terminal device, as described above, the latest offered load related to an application in wireless communication in its own cell may be received from the wireless base station. .

  As described above, according to the wireless communication device 1 according to the present embodiment, the boundary information is adjusted according to the success or failure of the reception of the wireless communication after the change of the wireless resource allocation according to the prediction. The boundary information can be adjusted to improve the accuracy of prediction. As a result, more wireless communications can be accommodated than when fixed boundary information is used. In particular, this is considered to be remarkable in an overload state.

  In addition, in this Embodiment, before performing the prediction regarding the accommodation capability of radio | wireless communication in the case where the radio | wireless resource utilization condition of an own cell increases, the prediction part 24 is the present cell's current utilization condition and the other cell's current utilization condition, It may be determined whether or not the boundary is an accommodable side. And when the own cell present use condition etc. are the accommodation possible side, you may make it perform the prediction.

  Next, prediction regarding whether or not wireless communication can be accommodated when the radio resource utilization status of the own cell decreases will be described. Before making this prediction, the prediction unit 24 first determines whether the current cell current usage status and the other cell current usage status are on the unaccommodable side from the boundary line, and the current cell current usage status etc. The prediction is made only when it is possible. This is because it is not necessary to make a prediction regarding whether or not the wireless communication can be accommodated when the wireless resource utilization state of the own cell decreases unless the current utilization state of the own cell is the unaccommodable side. Also in this prediction, similarly to (A) and (B) described above, (C) prediction regarding whether or not wireless communication can be accommodated according to offer load reduction may be performed, and (D) accommodation is possible in the own cell. Therefore, prediction regarding wireless communication to be reduced may be performed. When performing these predictions, the current cell current usage status and the other cell current usage status are on the unaccommodable side from the boundary line. Moreover, the formula which shows the relationship between the own cell utilization condition and other cell utilization condition in the accommodation impossible side may differ from the relational expression in the accommodation possible side (refer the said nonpatent literature 1). Therefore, when performing prediction of (C) and (D), the prediction unit 24 may perform prediction using a relational expression on the unaccommodable side different from the relational expression on the accommodable side, or can be accommodated. Approximation may be predicted using the relational expression on the side. In the former case, the relational expression specifying unit 23 may specify the relational expression on the unaccommodable side in the same manner as Expression (8). In the latter case, the relational expression specifying unit 23 specifies the relational expression on the accommodable side as described above. Hereinafter, the prediction of (C) and (D) will be described.

(C) Prediction on availability of radio communication according to offer load reduction The prediction unit 24 uses the own cell usage status after reducing the offered load of radio communication in the own cell to reduce the offered load. It may be determined whether or not the wireless communication can be accommodated according to the situation. The reduction of the offered load refers to the reduction of the offered load to be performed in the future. For example, when an application that is currently performing wireless communication is to be terminated in the future, the current offered load of the application becomes the offered load to be reduced. For example, the prediction unit 24 may receive an offer load to be reduced from the processing unit 13 or the like. Then, the prediction unit 24 calculates the own cell usage state after reducing the offered load to be reduced. Further, the prediction unit 24 acquires the other cell usage status corresponding to the own cell usage status after the offer load reduction using the relational expression specified by the relational expression specifying unit 23, and the own cell usage status or the like is obtained. It is determined whether or not the boundary indicated by the boundary information exists on the accommodable side. And the prediction part 24 may judge that it can accommodate, when the own cell use condition etc. exist in the accommodable side of a boundary line. This prediction may be used, for example, to determine which application among the applications currently being wirelessly communicated will be accommodated in the future.

(D) Prediction regarding radio communication to be reduced to be accommodable in own cell Even if the prediction unit 24 acquires the radio resource usage status corresponding to the radio communication to be reduced to allow the own cell to be accomodated Good. And the prediction part 24 may acquire the reduction information which is the information regarding the radio | wireless communication which should be reduced in order to be able to accommodate an own cell using the acquired radio | wireless resource utilization condition. The reduction information may be the radio resource usage status itself to be reduced, or may be information obtained by converting the radio resource usage status into offered load or other information. The prediction unit 24 acquires the own cell usage status at the intersection of the relational expression specified by the relational expression specifying unit 23 and the boundary indicated by the boundary information, and subtracts the own cell usage status from the current cell current usage status. . The value of the subtraction result is the radio resource usage status to be reduced in the own cell. Note that, as described above, the reduction information may be acquired by converting the radio resource usage status into offered load or the like.

  In addition, when the prediction unit 24 performs prediction of (A) and / or (C), the prediction unit 24 uses the own cell usage state after changing the offered load of wireless communication in the own cell. Therefore, it is determined whether or not the wireless communication can be accommodated according to the change in the offered load. The own cell usage status after changing the offered load is, for example, the own cell usage status after adding an additional offered load or the own cell usage status after reducing the offered load. The offered load fluctuation is, for example, addition or reduction of the offered load.

  In addition, a brief description will be given of prediction regarding whether or not to accommodate radio communication when the radio resource utilization status of other cells increases or decreases. Up to this point, the prediction regarding the availability of wireless communication when the own cell usage status increases or decreases has been described, but the same prediction is made when the other cell usage status increases or decreases You may go to The prediction includes, for example, prediction regarding wireless communication that can be additionally accommodated in other cells, prediction regarding wireless communication that should be reduced in other cells in order to be accommodated. When the wireless communication device 1 can receive an additional offered load or an offered load to be reduced from another cell, the prediction unit 24 accommodates the wireless communication according to the additional offered load in the other cell. Prediction regarding availability may be performed, or prediction regarding availability of radio signals according to reduction of offered load in other cells may be performed. These predictions are the same as those described above except that the own cell and other cells are changed, and the detailed description thereof is omitted. Moreover, the prediction result may be transmitted to, for example, a radio base station of another cell, or may be transmitted by including the radio base station of the own cell in a beacon or the like.

Further, in the present embodiment, a case has been described in which the adjustment unit 27 performs both the adjustment for increasing the margin M of the boundary line and the adjustment for decreasing the margin M, but this need not be the case. For example, the adjustment unit 27 may adjust the boundary information only in the direction in which the area that cannot be accommodated increases, or may adjust the boundary information only in the direction in which the area that can be accommodated increases. In the former case, for example, the initial value of the margin M is set to M _min (that is, the boundary information is set so that the accommodable area becomes the largest), and then the adjustment unit 27 determines that the incapable area is The boundary information may be adjusted in the increasing direction, and the adjustment may be terminated when it is determined that the determination unit 25 can accommodate the boundary information. In the latter case, for example, the initial value of the margin M is set to M _max (that is, boundary information is set so that the unaccommodable area becomes the largest), and then the adjustment unit 27 determines that the accommodable area is The boundary information may be adjusted in the increasing direction, and when the determination unit determines that the boundary information cannot be accommodated, the adjustment may be completed by returning to the previous boundary information. When such adjustment in only one direction is performed, as described above, the prediction unit 24 performs prediction using a boundary line including a margin in advance. Therefore, it may be considered that the prediction by the prediction unit 24 using the boundary information includes prediction using boundary information including a margin in advance as an initial value.

  Moreover, although this Embodiment demonstrated the case where processing, such as acquisition of an own cell present use condition, was performed for every control slot, it may not be so. For example, when the control slot is sufficiently long, the current cell current usage status acquired for a part of the control slot may be used as the current cell current usage status of the control slot.

  Moreover, although this Embodiment demonstrated the case where the radio | wireless communication apparatus 1 was provided with the accommodation prediction apparatus 2, it may not be so. The accommodation prediction device 2 is a device that accepts the own cell usage status, other cell usage status, etc. from the radio base station or radio terminal device, makes predictions using them, and passes the prediction results to the radio base station or radio terminal device It may be. In this case, the exchange of information between the accommodation prediction device 2 and the wireless base station or wireless terminal device may be performed by, for example, wired or wireless communication, and is performed via a cable or other interface. It may be broken.

  Moreover, although this embodiment demonstrated the case where the accommodation prediction apparatus 2 was provided with the history information storage part 26, it may not be so. When the accommodation prediction device 2 does not include the history information accumulation unit 26, the adjustment unit 27 does not need to determine whether or not to perform adjustment using the history information.

  In the above embodiment, each process or each function may be realized by centralized processing by a single device or a single system, or may be distributedly processed by a plurality of devices or a plurality of systems. It may be realized by doing.

  In the above embodiment, the information exchange between the components is performed by one component when, for example, the two components that exchange the information are physically different from each other. It may be performed by outputting information and receiving information by the other component, or when two components that exchange information are physically the same, one component May be performed by moving from the phase of the process corresponding to to the phase of the process corresponding to the other component.

  In the above embodiment, information related to processing executed by each component, for example, information received, acquired, selected, generated, transmitted, or received by each component In addition, information such as threshold values, mathematical formulas, addresses, and the like used by each component in processing may be temporarily or for a long time held in a recording medium (not shown), even if not specified in the above description. Further, the storage of information in the recording medium (not shown) may be performed by each component or a storage unit (not shown). Further, reading of information from the recording medium (not shown) may be performed by each component or a reading unit (not shown).

  In the above embodiment, when information used by each component, for example, information such as a threshold value, an address, and various setting values used by each component may be changed by the user, Even if it is not specified in the description, the user may be able to change the information as appropriate, or may not be so. If the information can be changed by the user, the change is realized by, for example, a not-shown receiving unit that receives a change instruction from the user and a changing unit (not shown) that changes the information in accordance with the change instruction. May be. The change instruction received by the receiving unit (not shown) may be received from an input device, information received via a communication line, or information read from a predetermined recording medium, for example. .

  In the above embodiment, when two or more components included in the wireless communication device 1 or the accommodation prediction device 2 include a communication device, an input device, or the like, the two or more components are physically single devices. Or may have separate devices.

  In the above embodiment, each component may be configured by dedicated hardware, or a component that can be realized by software may be realized by executing a program. For example, each component can be realized by a program execution unit such as a CPU reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory. At the time of execution, the program execution unit may execute the program while accessing the storage unit or the recording medium. In addition, the software which implement | achieves the accommodation prediction apparatus in the said embodiment is the following programs. In other words, this program allows the computer to interfere with the own cell usage status acquisition unit that acquires the current usage status of the own cell, which is the current radio resource usage status of the own cell in which the radio communication device performs radio communication, and the like. The other cell usage status acquisition unit that acquires the current usage status of the other cell that is the current usage status of the cell, the current usage status of the own cell, and the current usage status of the other cell. Relational expression specifying unit for specifying a relational expression indicating a relationship between a cell usage status and a radio resource usage status of another cell, a local cell usage status when radio communication can be accommodated in the local cell, and Shows the relationship between the other cell usage status and the own cell usage status and other cell usage status according to the boundary between the own cell usage status and the other cell usage status when wireless communication cannot be accommodated in the own cell. Using the boundary information, the relational expression identified by the relational expression identifying unit, and the current cell current usage status, a prediction unit that performs prediction regarding whether or not wireless communication can be accommodated, and a range predicted to be accommodable by the prediction unit As an adjustment unit that adjusts the boundary information according to the determination result by the determination unit when the radio resource allocation of the own cell is changed so that the wireless communication can be accommodated in the own cell after the change The prediction unit performs the prediction using the boundary information adjusted by the adjustment unit.

  In the program, the functions realized by the program do not include functions that can be realized only by hardware. For example, functions that can be realized only by hardware such as a modem or an interface card in an acquisition unit that acquires information, an output unit that outputs information, and the like are not included in at least the functions realized by the program.

  Further, this program may be executed by being downloaded from a server or the like, and a program recorded on a predetermined recording medium (for example, an optical disk such as a CD-ROM, a magnetic disk, a semiconductor memory, or the like) is read out. May be executed by Further, this program may be used as a program constituting a program product.

  Further, the computer that executes this program may be singular or plural. That is, centralized processing may be performed, or distributed processing may be performed.

  FIG. 7 is a schematic diagram illustrating an example of an external appearance of a computer that executes the program and realizes the wireless communication device 1 and the accommodation prediction device 2 according to the embodiment. The above-described embodiment can be realized by computer hardware and a computer program executed on the computer hardware.

  7, the computer system 900 includes a computer 901 including a CD-ROM drive 905, a keyboard 902, a mouse 903, and a monitor 904.

  FIG. 8 is a diagram showing an internal configuration of the computer system 900. In FIG. 8, in addition to the CD-ROM drive 905, a computer 901 is connected to an MPU (Micro Processing Unit) 911, a ROM 912 for storing a program such as a bootup program, and the MPU 911, and receives instructions of an application program. A RAM 913 that temporarily stores and provides a temporary storage space, a hard disk 914 that stores application programs, system programs, and data, and a bus 915 that interconnects the MPU 911, the ROM 912, and the like are provided. The computer 901 may include a network card (not shown) that provides connection to a LAN, WAN, or the like.

  Programs for causing the computer system 900 to execute the functions of the wireless communication device 1 and the accommodation prediction device 2 according to the above-described embodiments are stored in the CD-ROM 921, inserted into the CD-ROM drive 905, and transferred to the hard disk 914. Also good. Instead, the program may be transmitted to the computer 901 via a network (not shown) and stored in the hard disk 914. The program is loaded into the RAM 913 when executed. The program may be loaded directly from the CD-ROM 921 or the network. Further, the program may be read into the computer system 900 via another recording medium (for example, a DVD) instead of the CD-ROM 921.

  The program does not necessarily include an operating system (OS), a third-party program, or the like that causes the computer 901 to execute the functions of the wireless communication device 1 and the accommodation prediction device 2 according to the above-described embodiment. The program may include only a part of an instruction that calls an appropriate function or module in a controlled manner and obtains a desired result. How the computer system 900 operates is well known and will not be described in detail.

  Further, the present invention is not limited to the above-described embodiment, and various modifications are possible, and it goes without saying that these are also included in the scope of the present invention.

  As described above, according to the wireless communication device and the like according to the present invention, boundary information can be adjusted so as to improve the accuracy of prediction related to the availability of wireless communication. For example, a wireless communication device that performs assignment control of wireless resources, etc. Useful as.

DESCRIPTION OF SYMBOLS 1 Wireless communication apparatus 2 Accommodation prediction apparatus 11 Communication part 12 Control part 13 Processing part 21 Self-cell utilization condition acquisition part 22 Other cell utilization condition acquisition part 23 Relational expression specific part 24 Prediction part 25 Judgment part 26 History information storage part 27 Adjustment part

Claims (9)

The own cell usage status acquisition unit that acquires the current usage status of the own cell that is the current radio resource usage status of the own cell in which the radio communication device performs radio communication;
Other cell usage status acquisition unit for acquiring the current usage status of other cells, which is the current radio resource usage status of other cells that can interfere with the own cell;
Using the own cell current usage status and the other cell current usage status, the relationship between the own cell usage status that is the radio resource usage status of the own cell and the other cell usage status that is the radio resource usage status of the other cell A relational expression specifying unit that specifies a relational expression indicating
Depending on the boundary between the own cell usage status and other cell usage status when wireless communication can be accommodated in the own cell, and the own cell usage status and other cell usage status when wireless communication cannot be accommodated in the own cell Using the boundary information indicating the relationship between the own cell usage status and the other cell usage status, the relational expression specified by the relational expression specifying unit, and the own cell current usage status, to predict whether the wireless communication can be accommodated. A predictor to perform,
When the allocation of radio resources of the own cell is changed so that the range predicted to be accomodable by the prediction unit is changed, a determination unit that determines whether radio communication can be accommodated in the own cell after the change,
An adjustment unit that adjusts the boundary information according to a determination result by the determination unit,
The prediction unit is an accommodation prediction device that performs prediction using boundary information adjusted by the adjustment unit. The accommodation prediction device according to claim 1, wherein the adjustment unit adjusts the boundary information so that an area that cannot be accommodated increases when the determination unit determines that wireless communication cannot be accommodated in the own cell. . Wireless communication is performed by multiple applications,
The determination unit determines whether the wireless communication can be accommodated in the own cell for each application,
When the determination unit determines that wireless communication cannot be accommodated in its own cell, the adjustment unit increases the number of applications that are determined to be unacceptable, so that the area that cannot be accommodated increases. The accommodation prediction apparatus according to claim 2, wherein the boundary information is adjusted. The said adjustment part adjusts the said boundary information so that the area | region which can be accommodated will increase, when the said judgment part judges that radio | wireless communication could be accommodated in the own cell. The accommodation prediction apparatus as described. The prediction unit, using the relational expression, predicts the own cell usage status and other cell usage status according to the change of the allocation of radio resources of the own cell in the accommodable range,
The determination unit determines whether radio communication can be accommodated in the own cell after the change when the radio resource allocation of the own cell is changed so as to be the own cell usage status predicted by the prediction unit;
The adjustment unit is determined by the determination unit that radio communication can be accommodated in the own cell, and the allocation of radio resources in the own cell is changed so that the use state predicted by the prediction unit is established. When the own cell current use status and other cell current use status are within a predetermined range from the own cell use status and other cell use status predicted by the prediction unit, the area that can be accommodated increases. The accommodation prediction apparatus according to claim 4, wherein the boundary information is adjusted. A history information storage unit that stores history information including at least past determination results by the determination unit;
When the adjustment unit predicts that the determination result according to the adjusted boundary information cannot accommodate wireless communication in its own cell using the history information accumulated by the history information accumulation unit The accommodation prediction apparatus according to claim 1, wherein the adjustment is not performed. The accommodation prediction device according to any one of claims 1 to 6,
A communication unit for performing wireless communication;
And a control unit that controls allocation of radio resources related to radio communication performed by the communication unit according to a prediction result by the prediction unit. The own cell usage status acquisition step for acquiring the current usage status of the own cell which is the current radio resource usage status of the own cell in which the radio communication device performs radio communication;
Other cell usage status acquisition step of acquiring the current usage status of other cells, which is the current radio resource usage status of other cells that can interfere with the own cell;
Using the own cell current usage status and the other cell current usage status, the relationship between the own cell usage status that is the radio resource usage status of the own cell and the other cell usage status that is the radio resource usage status of the other cell A relational expression specifying step for specifying a relational expression indicating
Depending on the boundary between the own cell usage status and other cell usage status when wireless communication can be accommodated in the own cell, and the own cell usage status and other cell usage status when wireless communication cannot be accommodated in the own cell Using the boundary information indicating the relationship between the own cell usage status and the other cell usage status, the relational expression specified in the relational expression specifying step, and the current own cell current usage status, to predict whether the wireless communication can be accommodated. Prediction steps to perform,
A determination step of determining whether or not radio communication can be accommodated in the own cell after the change when the allocation of radio resources of the own cell is changed so that the range predicted to be accomodable in the prediction step;
An adjustment step of adjusting the boundary information in accordance with a determination result in the determination step,
An accommodation prediction method in which the prediction step performs prediction using the boundary information adjusted in the adjustment step. Computer
The own cell usage status acquisition unit for acquiring the current usage status of the own cell, which is the current radio resource usage status of the own cell in which the radio communication device performs radio communication,
Other cell usage status acquisition unit for acquiring the current usage status of other cells, which is the current radio resource usage status of other cells that may interfere with the own cell,
Using the own cell current usage status and the other cell current usage status, the relationship between the own cell usage status that is the radio resource usage status of the own cell and the other cell usage status that is the radio resource usage status of the other cell A relational expression specifying unit for specifying a relational expression indicating
Depending on the boundary between the own cell usage status and other cell usage status when wireless communication can be accommodated in the own cell, and the own cell usage status and other cell usage status when wireless communication cannot be accommodated in the own cell Using the boundary information indicating the relationship between the own cell usage status and the other cell usage status, the relational expression specified by the relational expression specifying unit, and the own cell current usage status, to predict whether the wireless communication can be accommodated. Predictor to perform,
When the allocation of radio resources of the own cell is changed to be within the range predicted to be accomodable by the prediction unit, a determination unit that determines whether radio communication can be accommodated in the own cell after the change,
Function as an adjustment unit that adjusts the boundary information according to a determination result by the determination unit;
The said prediction part is a program which performs the prediction using the boundary information adjusted by the said adjustment part.